A common idea promoted across the industry is that any heat lost from an uninsulated duct system to a conditioned space isn’t truly lost and has no effect on energy consumption. Most contractors would never consider installing uninsulated ducts in a vented attic or crawlspace but regularly do in basements and foamed attics.
Is it possible there are negative effects caused by uninsulated ducts in conditioned spaces we may have overlooked for decades? Let’s look at some problems you might encounter due to this practice and how you can determine the impact on the performance of your systems.